How about Music Masters and Liberty Music in midtown Manhattan? Both are long gone now but were primo sources for vinyl, particularly hard-to-find and esoteric stuff. Liberty (at 50th and Madison) was reportedly the oldest music store in the country and could trace their lineage all the way back to when it was a sheet music and musical instrument emporium and their customers arrived by horse-drawn carriage. Music Masters was the musical equivalent of a turn-of-the-century (19th, that is) bookstore and made up for its cramped quarters and rather inelegant decor with an awesome selection and the promise that if they didn't have it they'd do backflips until they located a copy for you.